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Archimago measures Ethernet cables


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18 minutes ago, Telecine said:

 

In fact it is a very good example of the robustness of the protocols and stack, working as designed over a variety of equipment and connections while reserving the integrity of the jitter prone data.

On a basic level you are no doubt  correct.

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27 minutes ago, Stereophilus said:

And you will note that I was careful to describe that the concern was not with the specifics of the electrical signal.

But hang on... isn't that what exotic cables are supposed to affect... the very signal that produces the the sound?

 

28 minutes ago, Stereophilus said:

Yes it is appropriate to do that, but there is possibly a broader issue at play that is neglected in isolated testing.  This is an unproven theory, and conjecture on my part. 

 

When the claim is that the cable is responsible for any improvement, then it is critical to examine that piece of equipment in complete isolation to the rest of the system.

 

30 minutes ago, Stereophilus said:

Sure.  But I'm curious and I believe we can do better than resorting to questionable methodology and faulty assumptions.

 

Like relying on uncalibrated equipment to evaluate very subtle changes that may or may not be evident?

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6 hours ago, bob_m_54 said:

But hang on... isn't that what exotic cables are supposed to affect... the very signal that produces the the sound?

 

 

When the claim is that the cable is responsible for any improvement, then it is critical to examine that piece of equipment in complete isolation to the rest of the system.

I understand that designers may make a claim, but their claims are not what I was talking about.

 

6 hours ago, bob_m_54 said:

Like relying on uncalibrated equipment to evaluate very subtle changes that may or may not be evident?

Uncalibrated equipment? Why would we introduce more error?  Your assertions here seem to be based on undermining scientific curiosity with faulty methodology.

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7 hours ago, Telecine said:

 

In fact it is a very good example of the robustness of the protocols and stack, working as designed over a variety of equipment and connections while preserving the integrity of the jitter prone data.

I'd argue the best representation of an ultra low latency network with no errors in data being the high frequency trading networks that rule our financial systems today. It's out of sight of many not connected to the industry but this is where protocols and connectivity have been tested to the ultimate performance limits achievable today, all in the aim of executing a trade faster than your neighbour.  

 

All of the technology from HFT is available in the wider ethernet manufacturer community and has trickled down to home users through common code trains and ASICS in switches. If you want to build the optimal networking stack from your $100 service provider Netgear modem to your esoteric boutique operating system music player, there's no secrets and no need for expensive cables.

 

If people saw the cables used in every hop (aside from your last hop in the lounge room) from the origination point to where you render the music, you'd find nothing more than standards meeting cables, acquired as cheaply as possible, and at volume. Networks, their components and cabling have been commoditised for well over a decade. There is no other industry, from audio and video production, to high frequency trading, to IP telephony networking to content distribution networks that uses "audiophile" cables.

 

The only purchasers of these cables are people who think they can hear different results using a new cable for the last hop in a massively complex network that was engineered using extremely robust science over decades. 

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30 minutes ago, Stereophilus said:

undermining scientific curiosity

 

When investigating my ability ability to levitate, it is not scientific curiosity to look at deficiencies in quantum gravity for the explanation. 
It is however, scientific curiosity to look at psychology to explain my ability.  
 

 

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13 minutes ago, Steffen said:

If someone sold a gadget that makes the sun rise in the west, I’m sure there would be people who “keep an open mind” about that, too. I wonder where they would draw the line?

 

Often attributed to Carl Sagan but it turns out the quote didn't come from him. Nonetheless it's still valid.

 

image.png.b2bf34bc4b4ce5519c03a9da8df83957.png

 

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27 minutes ago, Ittaku said:

 

Often attributed to Carl Sagan but it turns out the quote didn't come from him. Nonetheless it's still valid.

 

image.png.b2bf34bc4b4ce5519c03a9da8df83957.png

 

 

I also like Terry Pratchett's version:

 

The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it.”

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3 hours ago, sir sanders zingmore said:

 

I also like Terry Pratchett's version:

 

The trouble with having an open mind, of course, is that people will insist on coming along and trying to put things in it.”

Terry is a masterful writer.  I do hope hope the ironic humour in this quote is not lost on you.

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I was going to post some smartar*e comment about originality psychology and engineering but now I really can’t be bothered and I’m going to listen to some music. Teraphonic Overdubs by Chris Joss should calm the farm. 

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There’s always this if you want to have a laugh:

https://arstechnica.com/gadgets/2015/07/340-audiophile-ethernet-cable-gets-a-marginal-pass-on-the-test-bench/
 

There are two conclusions that can be drawn from the BJC analysis and the on-stage testing. First, at least for the sample tested, the $340 AudioQuest Vodka cable only marginally passes the TIA/ISO Cat6a signaling standard. Secondly, when using them to listen to NAS-hosted audio files via SMB, the Vodka Ethernet cables have roughly the same effect on your music as do $2.50 cables that fail the Cat6 spec with unacceptable levels of near-end crosstalk and return loss.”

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1 hour ago, rmpfyf said:

Could go on. 

 

I strongly suspect you are not being understood by the layperson.

 

Perhaps I can ask my question a different way, and you can try to give an answer we could more easily "get" ?! ;)

 

When I see a picture like this:   http://3.bp.blogspot.com/-hUTKRa30kLY/VN8OgvHr7FI/AAAAAAAAEKk/obTtgEnAmg0/s1600/Composite%2BJ-Test.jpg   This is the "J-test" of 7 different cables overlaid on each other.

 

 

I conclude that none of those cables produced an audibly different result..... because all of the non-linear distortion components are miles below my system SPL noise floor.   I don't make any conclusions about "jitter" ..... only that "whatever happened didn't matter" (as the analogue output have insignificant differences).

 

What generally have I misunderstood?

 

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35 minutes ago, rmpfyf said:

 

I strongly suspect you are correct. The stiff end of DSP is usually only covered in specialist, postgraduate-level engineering or science courses. I'm not suggesting it's not for the layperson, simply that it is hard stuff and by nature difficult to convey with general ease.

 

That's not me trying to be a d***; I'd neither ask a heart surgeon how to run a bypass operation in 25 minutes or less on Youtube for the layperson. 

 

 

Above all, this is not a measure of SPL.

 

What you are looking at is a spectral representation of a single frequency. It states 'if, for every data point on this graph, you made a sine wave of the ampltide of each of these points, you'd broadly get the one waveform equalling the input'. It is as audible as the input signal - if the input is audible, so is the output. There is no 'but at x Hz there's a tone that's quieter than a frog's fart and audible only to audiophile dolphins maybe', that's a rudely incorrect interpretation. This appears to be a spectral representation of a single tone with jitter. That there is a spread around the peak means jitter is present in either the acquisition, original signal or both. 

 

The number of authoritative people claiming a limit as to what is reasonable here is sadly high and adds something to the notion of this not being the easiest thing ever to understand. I mean...

  • If anything 'jumped out' it would be an exceptionally broken result
  • The gap between the peak and 0dB is interesting and needs to be explored
  • The data closest to the peak is (much) more relevant for audible difference than stuff at the far ends of the plot (and you only need half that plot to reprsent the same amount of data)
  • It says nothing for the noise floor of the aquistion method, or whether that was subtracted

 

They're just comments on method - that's before audibility, which we know a good bit less of. We do understand something of masking effects with respect to sine sources - take that peak, draw a tight triangle about it and for most people most of the time what is going on sounds same same. 

 

My music tastes extend a good bit beyond Euclid's Greatest Hit and so such shadowing arguments don't really hold in an audibility context where one can point to one peak and say ah, see, this crap underneath and just to the sides doesn't really matter so much. Because real music is broadband, and the distrbution of crap then is similarly broadband and  much more significant in both relative amplitude and frequency distribution.

 

Definitely speaking, if you're listening to music and the spectral content of any jitter is superimposed on the music you're already hearing, which is audible, therefore whatever you add to it is audible. Or in English - when next a self-made authority points at a J-test result and goes 'ha! that bit right next door to the peak is xx dB below the peak, and that's basically inaudible'...

 

...the correct answer is 'd**khead you might listen to test tones over a glass of wine but the rest of us listen to music, and that sideband amplitude would in practice be parked on some musical content that I can hear. Last I checked audible + a bit more = yup still audible. And the content that was already parked there intending for me to listen to it has intrinsic jitter of it's own. This is before we get into interchannel issues. So what we're looking at is a net audible difference to something already audible. Thanks for the graph, i'll ignore the rest.'

 

The J-test is good for showing jitter at a fundamental level by exploiting a particular quirk of digital system. It can be used for relative tests where methods are robust and accuracy is good. 

 

It is a very long reach to apply a J-test result in an audibilty context. About the only thing known in science (ASR, Archimago etc don't qualify - soz) is that J-test results (let alone J-test results done poorly) do not equal a definitive audibility argument. Research ongoing.

 

 

I'm struggling to understand how any of this has anything to do with Ethernet cables which have standards and can be tested using industry standard test equipment.

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